Extension-bit.



No. 807,956. PATENTED DEC. 19, 1905. W. B. MGBLNEY.

EXTENSION BIT.

APPLICATION FILED MAR. l8.1905

W/T/VESSES INVENTUR %43/5 We Km QMWZZ I mlzrronuzr' WILLIAM B. MCELNEY, OF MERIDEN, CONNECTICUT.

EXTENSION-BIT.

Specification of Letters Patent.

Patented Dec. 19, 1905.

Application filed March 18, 1905. Serial No, 250,866.

To all whom it may concern.-

Be it known that I, IVILLIAM B. MoELNnY, a citizen of the United States of America, residing at Meriden, in the county of New Haven and State of Connecticut, have invented certain new and useful Improvements in Extension-Bits, of which the following is a specification.

This invention relates to woodworkingtools, and particularly to an extension-bit in which the extension-cutter is adjustably held in position against accidental displacement.

An object of this invention is to provide novel means for permitting the adjustment of the extension-cutter transversely of the shank and in the provision of novel means for hold ing the said extension-cutter against movement when the parts are in the position to clamp the cutter in place.

Furthermore, an object of this invention is to provide novel means whereby the mechanism for adjusting the extension-cutter(which adjusting means comprises a screw threaded in a recess of the extension-cutter) is held in engagement with the extension-cutter in a manner to prevent creeping or movement of the said extension-cutter after the proper adjustment is attained, provision being made for simultaneously forcing the extension-cutter into contact with a shoulder formed on the bit, whereby an interlocking joint is formed between the extension-cutter and the bit.

A still further object of this invention is to provide means for retaining the extensioncutter clamped in place in engagement with the edge of the clamp, the contacting surfaces of the said extension-cutter and clamp being beveled to insure a firm gripping action.

Finally, an object of this invention is to provide an extension cutter and securing means of the character noted possessing advantages in points of simplicity and efiiciency and proving at the same time comparatively inexpensive to manufacture.

With the foregoing and other objects in View the invention consists in the details of construction and in the arrangement and combination of parts, to be hereinafter more fully described and claimed.

In describing the invention in detail reference will be had to the accompanying drawings, forming part of this specification, where in like characters denote corresponding parts in the several views, and in which-- Figure 1 is a view in elevation showing a bit with the extension-cutter applied thereto which is slightly undercut.

C indicates a shoulder a suitable distance from the forward end of the bit. The said shoulders are produced by cutting away a portion of the bit to form stepped planes D and E, at the junction of which is a recess F, in which the adjusting-screw turns.

The extension-cutter H has a beveled edge I, conforming to the contour of the shoulder B, in order that the joint between the shoulder and the edge of the extension-cutter will prevent displacement of the cutter when in operation. The under surface of the cutter is provided with a transversely-disposed threaded recess J which coincides with the recess F, forming with the said recess F a socket for the reception of the adjusting-screw G. The

rear edge K of the extension-cutter is beveled for the purpose of causing the beveled edge of the clamp L to bind upon the beveled edge of the cutter and force the outer beveled surface I into engagement with the shoulder B. The clamp is held in place by the screw M which is threaded in the bit in the ordinary way.

In operation the proper adjustment of the extension-cutter with relation to the bit is effected by turning the screw G to the right or left, it being understood, of course, that the clamp L is released to permit this adjustment. WVhen the proper adjustment is attained, the screw M is driven in to cause the clamp to en gage and bind against the beveled edge of the extension-cutter, which action results in binding the parts in the position heretofore stated; efliectually preventing creeping of the extension-cutter under the most violent strain. will be observed that the force exerted on the extension-cutter by the clamp is downward and transversely of the said extension-cutter, thus, as stated, binding said extension-cutter against the screw and against the shoulder B.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

In a device of the character described, a

suitable bit having a transversely-disposed recess, the walls of which are in stepped relation, the said walls having a semicircular recess at the junction of the stepped walls, an extension-cutter slidable' transversely of the bit and having a threaded recess in its inner surface corresponding with the recess of the bit, forming in conjunction with said recess of the bit a socket, the inner surface of the said extension-cutter being stepped to engage the stepped surface of the bit, the inner edge of the said extension-cutter being beveled, an adjusting-screw within the socket; a clamp having a beveled edge contacting and coacting with the beveled surface of the extensio'n-cut- 5 ter, a screw extending through the clamp and threaded into the bit for forcing the clamp into engagement with the extension-cutter, and a shoulder on the bit against Which the extension-cutter is forced, as and for the pur- 2O pose described.

In testimony whereof I afiiX my signature,in the presence of two witnesses, this 24th day of 

